The Cape has had a shortage of dermatologists for years, so the arrival of Dr. Emily Tierney was welcome news to the many patients who have been traveling to Boston and Plymouth to see her at her practices in those locations. Her new practice, the Dermatology and Skin Surgery Center of Cape Cod at Cape Cod Healthcare's new Wilkins Outpatient Medical Complex in Hyannis, opened Nov. 15 and Tierney says the entire community has embraced her.

"I feel like I've been welcomed with open arms from all the physicians on the Cape," she says. "I've met with a lot of the other dermatologists here. I've met with the internists and everyone has just been so, so supportive and we've gotten so many referrals from the physicians on the Cape, which is very exciting."

Tierney says the Cape is not alone in having a shortage of dermatologists. Dermatology is a relatively small specialty and only about 300 dermatologists are trained each year. Not only is there a shortage in terms of numbers, but the demographics tend to be skewed with an overabundance of dermatologists in big cities like New York, San Francisco and Los Angeles and many fewer in rural areas.

In speaking with local physicians, she learned that a lot of internal medicine and family practice physicians have become well versed in screening for skin cancers out of necessity.

Skin cancer is on the rise, with more than 2.5 million cases diagnosed annually in the United States. The shortage of certified dermatologists becomes more pertinent in areas like the Cape or certain sections of Florida that have large populations of senior citizens.

"Primarily my professional interest is in skin cancer surgery," she says. "And I think it's very difficult for older patients who need skin cancer surgery to travel off the Cape for long distances. "

After her residency, Tierney did a one-year fellowship training in Mohs Micrographic surgery at the American College of Mohs Surgery in Indiana. Mohs surgery has been around since the late 1980s and about 30 to 50 fellows are trained each year in the technique. There are only about 800 members of the American College of Mohs Surgery across the country.

Mohs surgery is a special kind of skin cancer removal technique in which the surgeon does horizontal frozen sections, processing the tissue with a cryostat model that is the same machine used in pathology labs.

In a typical vertical sectioning technique, the skin cancer is removed and the entire specimen is sent to the lab. It takes a week for the pathologist to read the specimen to let the surgeon know if all the cancer was removed.

"With a horizontal section we are really able to cut through the entire cross-sectional area of the cancer so in the middle of the specimen we're looking at the bottom or the depth of it and around the perimeter we're looking at the entire circumference in 360 degrees," she says. "So the reason why Mohs is preferable is that we really are able to evaluate the entire histological specimen and that's why Mohs has a cure rate of between 95 and 99 percent for primary skin cancers. The cure rate for the standard excisional technique is between 80 and 90 percent."

Mohs also has the advantage of being less invasive in terms of appearance and is primarily designed for skin cancers on the head and neck, and for very aggressive skin cancers and skin cancers in patients with compromised immune systems.

Mohs surgery is a tissue-sparing operation because the surgeon takes only one to two millimeters of skin at a time and then processes it under the microscope to make sure all the cancer is removed. In a standard excisional surgery for skin cancers on the trunk or extremities, surgeons typically excise five millimeters of normal skin around the tumor to make sure they get it all.

"If you can imagine doing that on a person's nose, it's a very large and sizable defect, so Mohs has significant advantages, not only in the way we process the tissue but also as a tissue-sparing procedure allowing us to preserve as much normal tissue as possible," she says.

Since skin cancer can be so dangerous, Tierney says her staff carefully triages all telephone calls to make sure that anyone who needs urgent care can get in right away, in some cases on the same day. She does not plan to close off the practice and says when someone is concerned a mole might be atypical or that it might be melanoma or skin cancer, she wants that person to be able to get in to see her as soon as possible. Patient care is the best part of her job, she says, and one of the reasons she chose dermatology as her specialty.

"As a medical student we rotate through all of the various different clinical rotations and I really loved internal medicine disciplines," she says. "I also loved surgical disciplines and I loved pediatrics. Dermatology was one of the fields that I found where you really get to combine medicine, surgery and pediatrics. We treat a wide spectrum of different conditions and I love the diversity of it."